river/rivertile/main.zig
Isaac Freund 871fc7c8de river-options: remove protocol
This protocol involves far too much accidental complexity. The original
motivating use-case was to provide a convenient way to send arbitrary
data to layout clients at runtime in order to avoid layout clients
needing to implement their own IPC and do this over a side-channel.
Instead of implementing a quite complex but still rigid options protocol
and storing this state in the compositor, instead we will simply add
events to the layout protocol to support this use case.

Consider the status quo event sequence:

1. send get_option_handle request (riverctl)
2. roundtrip waiting for first event (riverctl)
3. send set_foo_value request (riverctl)
4. receive set_foo_value request (river)
5. send foo_value event to all current handles (river)
6. receive foo_value event (rivertile)
7. send parameters_changed request (rivertile)
8. receive parameters_changed request (river)
9. send layout_demand (river)

And compare with the event sequence after the proposed change:

1. send set_foo_value request (riverctl)
2. receive set_foo_value request (river)
3. send set_foo_value event (river)
4. send layout_demand (river)

This requires *much* less back and forth between the server and clients
and is clearly much simpler.
2021-04-27 00:10:20 +02:00

270 lines
11 KiB
Zig

// This file is part of river, a dynamic tiling wayland compositor.
//
// Copyright 2020-2021 The River Developers
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
// This is an implementation of the default "tiled" layout of dwm and the
// 3 other orientations thereof. This code is written for the main stack
// to the left and then the input/output values are adjusted to apply
// the necessary transformations to derive the other orientations.
//
// With 4 views and one main on the left, the layout looks something like this:
//
// +-----------------------+------------+
// | | |
// | | |
// | | |
// | +------------+
// | | |
// | | |
// | | |
// | +------------+
// | | |
// | | |
// | | |
// +-----------------------+------------+
const std = @import("std");
const mem = std.mem;
const assert = std.debug.assert;
const wayland = @import("wayland");
const wl = wayland.client.wl;
const river = wayland.client.river;
const Location = enum {
top,
right,
bottom,
left,
};
const default_main_location: Location = .left;
const default_main_count = 1;
const default_main_factor = 0.6;
const default_view_padding = 6;
const default_outer_padding = 6;
/// We don't free resources on exit, only when output globals are removed.
const gpa = std.heap.c_allocator;
const Context = struct {
initialized: bool = false,
layout_manager: ?*river.LayoutManagerV1 = null,
outputs: std.TailQueue(Output) = .{},
fn addOutput(context: *Context, registry: *wl.Registry, name: u32) !void {
const wl_output = try registry.bind(name, wl.Output, 3);
errdefer wl_output.release();
const node = try gpa.create(std.TailQueue(Output).Node);
errdefer gpa.destroy(node);
try node.data.init(context, wl_output, name);
context.outputs.append(node);
}
};
const Output = struct {
wl_output: *wl.Output,
name: u32,
layout: *river.LayoutV1 = undefined,
fn init(output: *Output, context: *Context, wl_output: *wl.Output, name: u32) !void {
output.* = .{ .wl_output = wl_output, .name = name };
if (context.initialized) try output.getLayout(context);
}
fn getLayout(output: *Output, context: *Context) !void {
assert(context.initialized);
output.layout = try context.layout_manager.?.getLayout(output.wl_output, "rivertile");
output.layout.setListener(*Output, layoutListener, output) catch unreachable;
}
fn deinit(output: *Output) void {
output.wl_output.release();
output.layout.destroy();
}
fn layoutListener(layout: *river.LayoutV1, event: river.LayoutV1.Event, output: *Output) void {
switch (event) {
.namespace_in_use => fatal("namespace 'rivertile' already in use.", .{}),
.layout_demand => |ev| {
const secondary_count = if (ev.view_count > default_main_count)
ev.view_count - default_main_count
else
0;
const usable_width = switch (default_main_location) {
.left, .right => ev.usable_width - 2 * default_outer_padding,
.top, .bottom => ev.usable_height - 2 * default_outer_padding,
};
const usable_height = switch (default_main_location) {
.left, .right => ev.usable_height - 2 * default_outer_padding,
.top, .bottom => ev.usable_width - 2 * default_outer_padding,
};
// to make things pixel-perfect, we make the first main and first secondary
// view slightly larger if the height is not evenly divisible
var main_width: u32 = undefined;
var main_height: u32 = undefined;
var main_height_rem: u32 = undefined;
var secondary_width: u32 = undefined;
var secondary_height: u32 = undefined;
var secondary_height_rem: u32 = undefined;
if (default_main_count > 0 and secondary_count > 0) {
main_width = @floatToInt(u32, default_main_factor * @intToFloat(f64, usable_width));
main_height = usable_height / default_main_count;
main_height_rem = usable_height % default_main_count;
secondary_width = usable_width - main_width;
secondary_height = usable_height / secondary_count;
secondary_height_rem = usable_height % secondary_count;
} else if (default_main_count > 0) {
main_width = usable_width;
main_height = usable_height / default_main_count;
main_height_rem = usable_height % default_main_count;
} else if (secondary_width > 0) {
main_width = 0;
secondary_width = usable_width;
secondary_height = usable_height / secondary_count;
secondary_height_rem = usable_height % secondary_count;
}
var i: u32 = 0;
while (i < ev.view_count) : (i += 1) {
var x: i32 = undefined;
var y: i32 = undefined;
var width: u32 = undefined;
var height: u32 = undefined;
if (i < default_main_count) {
x = 0;
y = @intCast(i32, (i * main_height) + if (i > 0) main_height_rem else 0);
width = main_width;
height = main_height + if (i == 0) main_height_rem else 0;
} else {
x = @intCast(i32, main_width);
y = @intCast(i32, (i - default_main_count) * secondary_height +
if (i > default_main_count) secondary_height_rem else 0);
width = secondary_width;
height = secondary_height + if (i == default_main_count) secondary_height_rem else 0;
}
x += @intCast(i32, default_view_padding);
y += @intCast(i32, default_view_padding);
width -= 2 * default_view_padding;
height -= 2 * default_view_padding;
switch (default_main_location) {
.left => layout.pushViewDimensions(
ev.serial,
x + @intCast(i32, default_outer_padding),
y + @intCast(i32, default_outer_padding),
width,
height,
),
.right => layout.pushViewDimensions(
ev.serial,
@intCast(i32, usable_width - width) - x + @intCast(i32, default_outer_padding),
y + @intCast(i32, default_outer_padding),
width,
height,
),
.top => layout.pushViewDimensions(
ev.serial,
y + @intCast(i32, default_outer_padding),
x + @intCast(i32, default_outer_padding),
height,
width,
),
.bottom => layout.pushViewDimensions(
ev.serial,
y + @intCast(i32, default_outer_padding),
@intCast(i32, usable_width - width) - x + @intCast(i32, default_outer_padding),
height,
width,
),
}
}
layout.commit(ev.serial);
},
.advertise_view => {},
.advertise_done => {},
}
}
};
pub fn main() !void {
const display = wl.Display.connect(null) catch {
std.debug.warn("Unable to connect to Wayland server.\n", .{});
std.os.exit(1);
};
defer display.disconnect();
var context: Context = .{};
const registry = try display.getRegistry();
registry.setListener(*Context, registryListener, &context) catch unreachable;
_ = try display.roundtrip();
if (context.layout_manager == null) {
fatal("wayland compositor does not support river_layout_v1.\n", .{});
}
context.initialized = true;
var it = context.outputs.first;
while (it) |node| : (it = node.next) {
const output = &node.data;
try output.getLayout(&context);
}
while (true) _ = try display.dispatch();
}
fn registryListener(registry: *wl.Registry, event: wl.Registry.Event, context: *Context) void {
switch (event) {
.global => |global| {
if (std.cstr.cmp(global.interface, river.LayoutManagerV1.getInterface().name) == 0) {
context.layout_manager = registry.bind(global.name, river.LayoutManagerV1, 1) catch return;
} else if (std.cstr.cmp(global.interface, wl.Output.getInterface().name) == 0) {
context.addOutput(registry, global.name) catch |err| fatal("failed to bind output: {}", .{err});
}
},
.global_remove => |ev| {
var it = context.outputs.first;
while (it) |node| : (it = node.next) {
const output = &node.data;
if (output.name == ev.name) {
context.outputs.remove(node);
output.deinit();
gpa.destroy(node);
break;
}
}
},
}
}
fn fatal(comptime format: []const u8, args: anytype) noreturn {
std.log.err(format, args);
std.os.exit(1);
}